360 rebuild need help

pghjeeper

Well as some of you know I've been plugging away at rebuilding a 78 360 for my CJ7. I have tons of new parts and had the heads re-built and built. I was planning on doing an upper end re-build as the motor ran fine and had great compression. Well I was pulling the brass freeze plugs out to replace them and the water jackets have a good bit of crap built up in the corners of them. So I was wondering if I can clean them out some way without tearing the rest of the block down? The truck didn't run hot when I pulled the motor but then again it wasn't out on the trails. If I have to do a re-build on the bottom end what can I expect to pay for a short block or a bottom end re-build? Anyone know any good shops to get an AMC short block in the PA,OH,WV area? Thanks

Mudrat

If your freeze plugs are out and heads are off, pressure wash the crap outta the inside as best you can, from every angle you can to get the bulk of the deposits. If it wasn't running hot before then I'd just put in new freeze plugs and run some cooling system flush thru it a couple times. Let the engine get hot so the heater core gets cleaned too. Make sure you clear-flush well between cooling system chemical flushes and especially AFTER before you add the antifreeze. Mudrat

fuzz401

pm sent to you

Mudrat

fuzz401 wrote
pm sent to you

You passing trade secrets without letting us know??? :idea:

pghjeeper

Tonight I found out that the engine will need a bottom end re-build also. Ppulled the cam and there is a ton of crud and build-up in there. The bearings don't look to bad but who wants the crude breaking loose and destroying the motor. I'm going to have them hot tank,check for cracks, new pitsons/rings, bearing, and balance the motor. I already have the heads all done, can/lifter, timing chain, etc. What should I expect to pay for the machine work? Balance and botom end labor?

pghjeeper

Fuzz thanks for the contact info, but I need the motor ASAP so I'm trying to stay close to Pittsburgh. I contacted a couple of local engine builder and also NAPA. I got prices ranging from 400.00-1400.00 with me providing the parts. That was for a short block rebuild with the highend including line boring and balanceing. I have a few more Q's 1.) Will I run into any problem punching it out .30 over? I heard of some heat issues with overobred AMC motors. 2.) Do I need to balance the motor? This is going to be a mainly off-road Jeep with less that 2k miles a year put on it.

jeepsr4ever

1.) You should be fine 2.) No you dont need a balance...you shouldnt need a balance when your rodding on it offroad....unless your holding your foot into it for extended periods of time (thats a whole different issue) 3.) Most places will sell you a rebuilt short block, check your local parts stores.

Mudrat

pghjeeper wrote
I got prices ranging from 400.00-1400.00 with me providing the parts. That was for a short block rebuild with the highend including line boring and balanceing.
I have a few more Q's
1.) Will I run into any problem punching it out .30 over? I heard of some heat issues with overobred AMC motors.
2.) Do I need to balance the motor? This is going to be a mainly off-road Jeep with less that 2k miles a year put on it.

$1400 seems kinda steep - I just had a 258 hot tanked, bored 30 over, line bored, crank ground and polished, rotating assy balanced with a new felx plate, and a 3* valve job on a straight 6, they provided everything including the bearings, and gasket set for that same price. :shock:

Except for the headers and intake, my daughter has a hell-uv-a motor in her Jeep!!!

pghjeeper

MC Thanks!! I kinda thought the same thing but a few of the shop wouldn't even touch the motor unless I balanced it also. Problem is Pittsburgh sucks for performance shops, unless you drive a rice burner with a fart tube stickin out the back and neon out the wazoo. I checked on the availability of short blocks and most of the places around here use ATK and they don't sell short blocks. If I could go that route I would

pghjeeper

Funny thing is the guy at NAPA told me you can't get parts for them AMC motors no more!!! When you tell people its an AMC 360 you would think I just told them its the motor from a Tucker. I had to tell the one guy you can still get parts for a 1991 Waggy at the Jeep dealer.

fuzz401

sounds like there way of telling you they dont want to work on it